Such rings should not give rise to sudden reactions in the event of the support to which they are fitted being caused to deform exceptionally.
On the contrary, the traction limit that they provide must be applied very progressively.
In one advantageous way that has been proposed for manufacturing such rings, a rubber sheath is molded around a ring made up of strong threads, particularly threads made of rayon, Kevlar or carbon (see French patent No. 2 586 278).
A particular object of the invention is to make rings of the kind in question that are simultaneously stronger in traction, easier to manufacture, and cheaper.